interface/wx/validate.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        validate.h
   3 // Purpose:     interface of wxValidator
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxValidator
  11
  12     wxValidator is the base class for a family of validator classes that
  13     mediate between a class of control, and application data.
  14
  15     A validator has three major roles:
  16
  17     -#  To transfer data from a C++ variable or own storage to and from a
  18         control.
  19     -#  To validate data in a control, and show an appropriate error message.
  20     -#  To filter events (such as keystrokes), thereby changing the behaviour
  21         of the associated control.
  22
  23     Validators can be plugged into controls dynamically.
  24
  25     To specify a default, "null" validator, use ::wxDefaultValidator.
  26
  27     For more information, please see @ref overview_validator.
  28
  29     @beginWxPythonOnly
  30     If you wish to create a validator class in wxPython you should derive the
  31     class from @c wxPyValidator in order to get Python-aware capabilities for
  32     the various virtual methods.
  33     @endWxPythonOnly
  34
  35     @library{wxcore}
  36     @category{validator}
  37
  38     @stdobjects
  39     ::wxDefaultValidator
  40
  41     @see @ref overview_validator, wxTextValidator, wxGenericValidator
  42 */
  43 class wxValidator : public wxEvtHandler
  44 {
  45 public:
  46     /**
  47         Constructor.
  48     */
  49     wxValidator();
  50
  51     /**
  52         Destructor.
  53     */
  54     virtual ~wxValidator();
  55
  56     /**
  57         All validator classes must implement the Clone() function, which
  58         returns an identical copy of itself.
  59
  60         This is because validators are passed to control constructors as
  61         references which must be copied. Unlike objects such as pens and
  62         brushes, it does not make sense to have a reference counting scheme to
  63         do this cloning because all validators should have separate data.
  64
  65         @return This base function returns @NULL.
  66     */
  67     virtual wxObject* Clone() const;
  68
  69     /**
  70         Returns the window associated with the validator.
  71     */
  72     wxWindow* GetWindow() const;
  73
  74     /**
  75         This functions switches on or turns off the error sound produced by the
  76         validators if an invalid key is pressed.
  77     */
  78     static void SetBellOnError(bool doIt = true);
  79
  80     /**
  81         Associates a window with the validator.
  82
  83         This function is automatically called by wxWidgets when creating a wxWindow-derived
  84         class instance which takes a wxValidator reference.
  85
  86         E.g.
  87         @code
  88         new wxTextCtrl(this, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, 0,
  89                        wxTextValidator(wxFILTER_ALPHA, &g_data.m_string));
  90         @endcode
  91         will automatically link the wxTextValidator instance with the wxTextCtrl
  92         instance.
  93     */
  94     void SetWindow(wxWindow* window);
  95
  96     /**
  97         This overridable function is called when the value in the window must
  98         be transferred to the validator.
  99
 100         @return @false if there is a problem.
 101     */
 102     virtual bool TransferFromWindow();
 103
 104     /**
 105         This overridable function is called when the value associated with the
 106         validator must be transferred to the window.
 107
 108         @return @false if there is a problem.
 109     */
 110     virtual bool TransferToWindow();
 111
 112     /**
 113         This overridable function is called when the value in the associated
 114         window must be validated.
 115
 116         @param parent
 117             The parent of the window associated with the validator.
 118
 119         @return @false if the value in the window is not valid; you may pop up
 120                 an error dialog.
 121     */
 122     virtual bool Validate(wxWindow* parent);
 123 };
 124
 125 /**
 126     An empty, "null" wxValidator instance.
 127 */
 128 wxValidator wxDefaultValidator;
 129